Display device



1935- L. w. ROSENTHAL El AL 3 DISPLAY DEVICE Filed Feb. 14, 1934 IN V EN T 0R5 l eon W Paaenf/za/ ;PJmme Meyer KQWJQJM 4, 4 ATTORNEY Patented Jan. 7, 1936 v UNITED STATES PATENT .oFFicE DISPLAY DEVICE Leon W. Rosenthal and Jerome 8.1107015 New York, N. Y.

Application February 14, 1984, Serial No. 711.182 3 Claims. (Cl. 88-18) This invention relates to animated display devices andmore particularly to such a device composed of a succession of graduated pictures past which the observer is carried at a fairly high speed. The principle of visual persistence is employed to create the illusion of continuous motion in the display characters and for this reason the presentation of successive images should be effected with aspeed of approximately 16 per second as the lower limit.

To accomplish this, the illumination may be obscured as by a shutter, or by providing a source of illumination that can be operated at this speed and which has a substantially instantaneous transition from light to darkness with little or no time lag between the phases. Preceding display systems of this character had thedisadvantage of presenting the image for too long a period of time, in which the observer moved an appreciable distance with respect to the image. This gave the successive images an apparent lateral motion in the eye of the observer and produced a streaked and cloudy appearance in the animated eifect presented. The present invention concerns a method by which the. combination ofthe vehicle and the display mechanism is made to present a succession of images of substantially instantaneous time duration and of high illumination, whereby the blurred effect of the former devices is overcome.

One object of this invention is to provide an animated display device adjacent the path of moving vehicles.

Another object is to utilize the motion of the vehicle as the means of presenting successive images to the eye of the observer.

Still another object is to provide momentary illumination of the images as they come successively into alignment with the various vehicle windows..

A still further object is to provide means auto-- matically controlled by the vehicle for properly synchronizing the flashes of illumination with the window openings regardless of vehicle speed.

Other objects will in part be obvious and in part be pointed out hereinafter.

To the attainment of the foregoing objects and ends, the invention still further resides in the novel details of construction, combination, and

arrangement of parts, all of which will first be fully described in the following detailed description, and then particularly pointed out in the appended claims, reference being had to the accompanying drawing, in which:

Fig. 1 is a perspective view of the-display de- -units as installed on a car; Fig. 3 is across section of a subway tube showing the mode of pro ducing and timing light pulsations; and Fig. 4 5 is a diagrammatic showing of a photo-electric cell with amplifier circuit and the manner of producing intermittent illumination of the light source.

-As shown in Fig. 1 the improved display system is installed in a subway tunnel. A succession of images is carried by a strip 1 of paper or any suitable material and secured to a support 2. The support 2 is mounted upon the successive subway girders 3 and carries a neon tube is 4 which is blackened in .the intervals between picture spaces. A succession of neon bulbs may be used in place of the tube 4, or any other suitable gaseous illuminating device. Control circuit 5 runs from the energizing source of the 20 neon tube to a photo-electric cell 6. From any suitable exciter lamp a beam 1' is directed across a portion of the subway tunnel and falls upon the photo-electric cell 6.

Fig. 2 shows the means for interrupting the 26 light beam at desired intervals. A metal strip carrying a series of vertical fins 8 is placed along the roof of the subway cars and is installed in such a manner that the projecting fins 8 are positioned above the windows and apertures of the car. As the car progresses, therefore, the light beam will be interrupted as each successive fin passes across, and the neon tube is caused to illuminate momentarily with the frequency of the passing fins 8. The images contained on as strip i are separated by the space approximating that separating the windows of the car so that there may be seen from each window an image momentarily illuminated according to the foregoing description.

Fig. 4 shows a photo-electric circuit known as a reverse circuit whereby the apparatus connected to the photo cell is operated only during periods of darkness upon the photo cell. The photo cell 6 has its anode connected to energizing bat- 45 tery 9 and its cathode connected to a control grid in of vacuum tube Ii. A grid leak l2, shunted by a parallel condenser I3, is connected at one end between the photocell cathode and the control grid I 0 and the other end is connected to a 50 slider arm of variable resistance It which is in series with-battery 8 and a biasing battery 0'. The cathode "of amplifier tube ii is energized by battery A. The anode I8 of tube II is connected to a circuit containing supply battery B 55 and I9 and 20 respectively. Accordingly when ,a shadow falls on the photo cell 8, the bias of,the grid 'ltl is made more positive and an impulse is transmitted through the anode circuit of tube I I, which energizes the relay coils I1 and I8 and causes the relays is and 20 to close supply ciras a convenience in analyzing the circuit and it. is obvious that such a circuit can be readily designed to operate from other sources of current.

In the operation of the display system, the neon tubes shave positioned at their adjoining ends a photo-electric control circuit therefor which controls one neon tube jointly with the preceding photo-electric circuit." This joint control is necessitated by the requirement that the lightsource must at all times be illuminated. for the full length of the passing car or train.

. A system which uses one photo-electric circuit to .control one illumination tube only, will cause the images opposite either the forward or the rear windows of the train to be without illumination. As the trains proceeds and builds up speed, the vertical fin 8 uponv the forward portion interrupts light beam 7 momentarily and causes an instantaneous flash of light in neon tube 4. The picture or e adjacent any window is therefore lighted during this period. The vertical fin 8 passes by the light beam 7 and allows it to strike the photo-electric cell 6, which momentarily darkens the neon tube. The next successive fin 8, which is positioned in alignment with the succeeding car window, then repeats the process. Therefore, an observer sitting in the car and traveling at a rapid rate can see from the adjacent window a succession of illuminated pictures passing in such rapid review that any characters difiering gradually would be given the appearance of a smooth, flowing motion;

claimed is:

' I accents 'n and is or double winding relays Due to the interconnecting control circuits of the neon tubes 4, the entire length 0! the car or train of cars will have presented before the windows thereof, the illuminated images. It has been found that the frequency with which these 5 images are presentedmay vary within the limits produced by the average speed of the subway cars in travel between stations without adversely affecting the operation of the improved display system. I v .10 While we have shown and described our invention as applied to a particular system and as embodying various devices shown and dlagrammatically indicated, changes and modii.cations will be obvious to those skilled in the art and is our object is therefore to cover all such changes and modifications as fall within the true spirit and scope of our invention.

Having described the invention, what is 1. In a display system, the combination of a moving vehicle having spaced apertures therein, fixed display characters spaced to accord with the spacing of said apertures, said characters being positioned in alignment with said apertures 26 and adjacent the path of travel of said vehicle, a single source of illumination for said, characters, and means for illuminating said source with the frequency of the passing vehicle apertures.

2. In a display system, the combination of a so moving vehicle having spaced apertures therein, a plurality of display characters positioned in alignment with said apertures and visible therethrough, a source oi illumination positioned ad- Jacent each of said characters, and means includto ing a switch for simultaneously illuminating and subsequently darkening said sources with the frequency of thepassing vehicle apertures.

3. In a display system, the combination of a moving vehicle having spaced apertures therein, 40 a plurality of display characters positioned in alignment with said apertures and visible therethrough, a single source of illumination positioned adjacent said characters, and means for illuminating said source with the frequency of 45 the passing vehicle apertures.

LEON w. ROSENI'HAL. JEROME s. MEYER. 

